<p>An air conditioner has: a casing 20 having an air inlet 21 and an air outlet 22; a heater 53 disposed in the casing 20 and heating air having flowed through the air inlet 21 into the casing 20; holders 54 and 55 holding the heater 53 and fitted to the casing 20; and a spacer 59 in contact with the heater 53 and disposed between the holders 54 and 55 and the heater 53. At least one of the heat-resistance and the flame-retardance of the spacer 59 is higher than that of the holders 54 and 55.</p>
